/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.innazis.jfrogsurvey.zxing.result;

import java.text.DateFormat;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Locale;

import android.app.Activity;

import com.innazis.jfrogsurvey.R;
import com.google.zxing.client.result.CalendarParsedResult;
import com.google.zxing.client.result.ParsedResult;

/**
 * Handles calendar entries encoded in QR Codes.
 * 
 * @author dswitkin@google.com (Daniel Switkin)
 */
public final class CalendarResultHandler extends ResultHandler {

	private static final DateFormat DATE_FORMAT = new SimpleDateFormat("yyyyMMdd", Locale.ENGLISH);
	private static final DateFormat DATE_TIME_FORMAT = new SimpleDateFormat("yyyyMMdd'T'HHmmss", Locale.ENGLISH);

	public CalendarResultHandler(Activity activity, ParsedResult result) {
		super(activity, result);
	}

	@SuppressWarnings("deprecation")
	@Override
	public CharSequence getDisplayContents() {
		CalendarParsedResult calResult = (CalendarParsedResult) getResult();
		StringBuilder result = new StringBuilder(100);
		ParsedResult.maybeAppend(calResult.getSummary(), result);
		Date start = calResult.getStart();
		String startString = start.toGMTString();
		appendTime(startString, result, false, false);

		Date end = calResult.getEnd();
		String endString = end.toGMTString();
		if (endString != null) {
			boolean sameStartEnd = startString.equals(endString);
			appendTime(endString, result, true, sameStartEnd);
		}

		ParsedResult.maybeAppend(calResult.getLocation(), result);
		ParsedResult.maybeAppend(calResult.getAttendees(), result);
		ParsedResult.maybeAppend(calResult.getDescription(), result);
		return result.toString();
	}

	private static void appendTime(String when, StringBuilder result, boolean end, boolean sameStartEnd) {
		if (when.length() == 8) {
			// Show only year/month/day
			Date date;
			synchronized (DATE_FORMAT) {
				date = DATE_FORMAT.parse(when, new ParsePosition(0));
			}
			// if it's all-day and this is the end date, it's exclusive, so show
			// the user
			// that it ends on the day before to make more intuitive sense.
			// But don't do it if the event already (incorrectly?) specifies the
			// same start/end
			if (end && !sameStartEnd) {
				date = new Date(date.getTime() - 24 * 60 * 60 * 1000);
			}
			ParsedResult.maybeAppend(DateFormat.getDateInstance().format(date.getTime()), result);
		} else {
			// The when string can be local time, or UTC if it ends with a Z
			Date date;
			synchronized (DATE_TIME_FORMAT) {
				date = DATE_TIME_FORMAT.parse(when.substring(0, 15), new ParsePosition(0));
			}
			long milliseconds = date.getTime();
			if (when.length() == 16 && when.charAt(15) == 'Z') {
				Calendar calendar = new GregorianCalendar();
				int offset = calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET);
				milliseconds += offset;
			}
			ParsedResult.maybeAppend(DateFormat.getDateTimeInstance().format(milliseconds), result);
		}
	}

	@Override
	public int getDisplayTitle() {
		return R.string.result_calendar;
	}
}
